Drain control means for liquid-containing vessel



J. BOCHAN 3,249,118

DRAIN CONTROL MEANS FOR LIQUID-CONTAINING VESSEL May 3, 1966 Filed Dec.4, 1963 INVENTOR. ITOHN BOCHAN BY W W HIS ATTORNEY United States Patent3,249,118 DRAIN CONTROL MEANS FOR LIQUID- CONTAINING VESSEL John Bochan,Louisville, Ky., assignor to General Electric Company, a corporation ofNew York FiledDec. 4, 1963, Ser. No. 327,981 Claims. (Cl. 137577) Thisinvention relates to drain control means for liquidcontaining vessels,and more particularly to gravity drain means which may selectivelypermit or prevent draining of liquid without any valve or pump means indirect contact with the liquid.

It is an object of this invention to provide an improved drain controlmeans for selectively preventing or permitting draining of liquidsthrough a conduit connected to a drain opening of the vessel.

More particularly, it is an object of my invention to achieve this goalwithout the use of a pump and without a valve in the drain line.

It is a further specific object of my invention to achieve liquid levelcontrol in the vessel by such means.

In one aspect of my invention, I provide drain control means comprisinga conduit having one end connected to the drain opening of aliquid-containing vessel, and the other end positioned below the drainopening so as to permit gravity-caused liquid flow through the conduit.

The conduit has a plurality of alternating downwardly and upwardlyextending sections; adjacent downwardly and upwardly extending sections,where they are joined at their respective tops, are selectively ventedto atmosphere. When the vent is closed, the back pressure of air trappedin the conduit causes liquid to be retained in the vessel; however, whenthe venting means is opened, there is no longer a back pressure of airand liquid thus drains out of the vessel as desired.

In the drawing, the single figure is a side elevational view, partlybroken away and partly in cross section to show details, of a clotheswashing machine in which a liquid-containing vessel incorporates theimproved drain control means of my invention.

Referring now to the figure of the drawing, there is shown therein, forpurposes of illustration, a vertical axis washing machine having aperforated clothes basket 1, with perforations 2 provided therein,disposed within an outer imperforate liquid-containing tub or vessel 3.Enclosing basket 1 and tub 3 is a frame in the form of an appearancecabinet'4 which includes a base 5 adapted to be seated on an appropriatefloor, vertically extending walls 6, and a lid 7 pivotable to an openposition to uncover opening 8 into the basket and tub. Secured on thetop of cabinet 4 there may be provided a conventional control panel 9.Control panel 9 may include a control member 10 to control the fillingof the vessel 3 with water, a member 11 to provide an agitating actionof basket 1, a member 12 to provide a centrifuging action of the basket,and an off switch 12a.

Within basket 1, suitable means such as vanes 13 may be provided foreffecting a circulatory motion of water contained therein in order toachieve washing of the clothes placed in the basket. The basket may berigidly secured on a shaft 14 extending upwardly from a motor 15 andtransmission 16 which cooperate, for one direction of motor rotation, toprovide an oscillating motion to shaft 14 and therefore to basket 1.This, in turn, through vanes 13, effects a washing action on theclothes. Motor 15 may be of the reversible type; when it is reversedfrom the direction of rotation in which oscillation of basket 1 occurs,it causes, through transmission 16, a continuous high speed rotation ofthe basket to centrifuge liquid out of the clothes contained therein.

A conventional solenoid-controlled valve 17 may be provided forcontrolling entry of water into the basket. It will 'be recognized thatsolenoid 17 is energized by depression of member 10 so as to causefilling of the basket. Member .11 causes rotation of motor 15 in thefirst direction so as to effect the washing movement of basket 1, andmember 12 causes the opposite rotation of the motor so as to effectcentrifuging action previously described.

A suitable suspension system for supporting the basket 1 and tub 3 isgenerally indicated by the numeral 18. Such a suspension system is fullydescribed and illustrated in Patent 3,026,700 issued on March 27, 1962,to John Bochan et al.; since the particular means of mounting theliquid-containing vessel has no significance insofar as my invention isconcerned, a detail description thereof will not be given herein.

At the bottom of vessel 3 there is provided an opening 19 through whichthe drain liquid may discharge into a conduit 20. It will be. observedthat the end of conduit 20 connects substantially horizontally withopening 19 so that the liquid will flow relatively smoothly along theconduit 20, rather than very suddenly filling it. Conduit 20 has aserpentine configuration made up of upwardly extending sections 21, 22,23 and 24 and downwardly extending sections 25, 26, 27 and 28, thedownwardly and upwardly extending sections alternating with each other.The adjoining upwardly extending section 21 and downwardly extendingsection 25 are joined at their tops by a section 29; similarly, sections22 and 26 are joined by section 30, and sections 23 and 27 are joined bysection 31. Top sections 29, 30 and 31, in my preferred embodimentshown, are no higher than the level of opening 19 as shown. In anyevent, they should be below the minimum liquid level desired to beretained within the vessel 3.

Top section 29 is joined by a conduit 32 to a small button-operated airvalve 33. Valve 33 either seals oil? the end of conduit 32 or vents itto atmosphere. Similarly, a conduit 34 controlled by a button-operatedvalve 35 is connected to top section 30, and a conduit 36 controlled bya button-operated valve 37 is connected to top section 31.

Let it be assumed that liquid is to be retained in vessel 3 up to levelA. As liquid pours into basket 1 and vessel 3, it will also flow throughopening 19 into the inlet end of conduit 20. The liquid will then flowalong through conduit 20 and up into section 21. When it reaches the topof section 21, liquid will flow over the bottom of th1s top section andstart to fill the U-shaped conduit portion which is made up of sections25 an 22; this flow is sufficiently slow so that it never requires thefull area of the conduit to pass it. As it does so, it will trap someair in conduit section 25 and tend to compress this air. As a result ofthe resistance of the air to such compression, the liquid rises morerapidly in section 22 than in section 25.

When the liquid reaches top section 30, it will again flow down to startfilling the conduit portion made up of sections 26 and 23; similarly towhat happened before,

air will be trapped in section 26 and will be compressed; this willresult in an even further compression of the air within section 25. 'Itwill be recognized that these air pockets thus created provide aresistance head to flow through the conduit, that is, they require thatthere be a substantial head of liquid before the liquid can overcome theresistance of the air pockets and flow through conduit 20 to the outlet38 thereof. Once the liquid gets up to the top of section 23, the samething happens again, that is, the portion made up of sections 27 and 24starts to fill with liquid and create an even higher back pressure.

The total back pressure is sufficient so that, if liquid is providedwithin vessel 3 up to level A, and all three vent valves 33, 35 and 37are closed, then the head of liquid existing as a result of the fillingof vessel 3 to level A Will not be sufiicient to overcome the resistanceprovided by the air pockets. Consequently, no liquid will flow out fromend 33 of conduit 20. Thus, liquid may be retained within the machinefor washing purposes by the use of simple small air vents rather than bya valve in the liquid line itself.

If, after the liquid has reached level A, the operator wishes todecrease the liquid level to line B in vessel 3, it is merely necessaryto open one of the vents which may, for instance, be vent 37. As soon asvent 37 is opened, the air trapped in section 27 will no longer becompressed and provide a back pressure. As a result of the eliminationof this back pressure, some of the liquid in the portion formed bysections 26 and 23 will flow over top 31 into sections 27 and 24. Whenthe liquid in sections 26 and 23 is thus moved, there is a decrease inthe pressure of the air pocket in section 26 and this decreased backpressure is eventually transmitted to the opening 19.

In other words, with less air trapped in the conduit 20, a smaller headof liquid is vessel 3 can be provided without liquid passing out throughopening 38. Consequently, liquid will drain out until the level hasdecreased from level A to level B and will then stop, with air pocketsstill present in sections 25 and 26. In the same way, level C can beobtained by opening vent 35 in addition to vent 37.

If no liquid at all is to be retained in the vessel 3, then all three ofthe vents 33, 35 and 37 are opened, and liquid will drain out of theconduit 20 so as to completely empty vessel 3. It will be seen that withall three vents open, basket 1 may be spun at high speed and that liquidthus centrifuged out of the clothes will flow down the walls of vessel 3and pass down through opening 19 into the conduit 20 so as to bedrained.

It can thus be seen that, without any direct contact with the liquidbeing drained, either by a pump or a valve, the liquid may either becaused to drain or be prevented from draining, and that this is done byeither causing air pockets providing back pressure, or eliminating theseair pockets by venting them to atmosphere.

It will readily be seen that many variations on this concept, and manyuses of it other than in a washing machine, are possible. For instance,if it were simply desired that the vessel be full or empty, all the ventconduits might be joined at the end at which they are vented, with asingle vent valve then controlling them. In addition, while theserpentine configuration shown is preferred, it will be obvious thatother arrangements may be provided. In fact, an ordinary coiled hose,with the axis of the coil generally horizontal, would be elfective toprovide the desired results if the proper selective connections toatmosphere were made at the tops of the coils.

Also, it will be apparent that inlet valve 17 may be controlled by aconventional pressure-responsive switch, schematically shown at 39,positioned to be responsive to the pressure in conduit 32. If this bedone, then valve 17 is shut off in the conventional way by switch 39when a predetermined liquid level in tub 3 has created a predeterminedpressure in conduit 32. By making switch 39 adjustable, the level invessel 3 at which valve 17 shuts off is also made adjustable.

Thus, while in accordance with the patent statutes I have described whatat present is considered to be the preferred embodiment of my invention,it will be obvious to those skilled in the art that various changes andmodifications may be made therein without departing from the invention,and I therefore aim in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. For use with a liquid-containing vessel having a drain opening formedtherein, drain control means comprising:

(a) a conduit having one end connected to said drain opening and itsother end positioned below said drain opening to permit gravity-causedliquid flow through said conduit, said conduit being formed with aplurality of alternating downwardly and upwardly extending sections,adjacent sections being joined at their respective tops below theminimum liquid level used in said vessel;

(b) and means for selectively venting said conduit to atmosphereconnected to at least one of said tops of adjacent sections, wherebyliquid is retained in said vessel when said venting means is closedanddrains out of said vessel when said venting means is opened.

2. The drain control means defined in claim 1 wherein said tops of saidadjacent sections are approximately at the height of said drain opening.

3. The drain control means defined in claim 1 wherein a plurality ofventing means are provided respectively connected to the tops ofadjacent sections, said venting means being individually operable toprovide for difierent levels of liquid within said vessel.

4. The drain control means defined in claim 1 wherein said conduit has aserpentine configuration.

5. For use with a liquid containing vessel having a drain opening formedtherein, drain and level control means comprising:

(a) a conduit having one end connected to said drain opening and itsother end positioned below said drain opening to permit gravity-causedliquid flow through said conduit, said conduit being formed with aplurality of alternating downwardly and upwardly extending sections,adjacent sections being joined at their respective tops below theminimum liquid level used in said vessel;

(b) liquid inlet means arranged to said vessel;

(c) means for selectively venting-said conduit to atmosphere connectedto at least one of said tops of adjacent sections, whereby liquid isretained in said vessel when said venting means is closed and drains outof said vessel when said venting means is open;

((1) and a pressure responsive switch connected to be responsive to thepressure at said one top of adjacent sections and controlling saidliquid inlet means so as to shut said liquid inlet means off when apredetermined pressure exists at said one top.

provide water to References Cited by thevExaminer UNITED STATES PATENTS753,174 2/1904 Smith 137--137 2,363,313 11/ 1944 Gavin. 2,612,903 6/1946Carnerero 137133 FOREIGN PATENTS 25,762 10/1904 Great Britain.

M. CARY NELSON, Primary Examiner. W. CLINE, Assistant Examiner.

1. FOR USE WITH A LIQUID-CONTAINING VESSEL HAVING A DRAIN OPENING FORMEDTHEREIN, DRAIN CONTROL MEANS COMPRISING: (A) A CONDUIT HAVING ONE ENDCONNECTED TO SAID DRAIN OPENING AND ITS OTHER END POSITIONED BELOW SAIDDRAIN OPENING TO PERMIT GRAVITY-CAUSED LIQUID FLOW THROUGH SAID CONDUIT,SAID CONDUIT BEING FORMED WITH A PLURALITY OF ALTERNATING DOWNWARDLY ANDUPWARDLY EXTENDING SECTIONS, ADJACENT SECTIONS BEING JOINED AT THEIRRESPECTIVE TOPS BELOW THE MINIMUM LIQUID LEVEL USED IN SAID VESSEL; (B)AND MEANS FOR SELECTIVELY VENTING SAID CONDUIT TO ATMOSPHERE CONNECTEDTO AT LEAST ONE OF SAID TOPS OF ADJACENT SECTIONS, WHEREBY LIQUID ISRETAINED IN SAID VESSEL WHEN SAID VENTING MEANS IS CLOSED AND DRAINS OUTOF SAID VESSEL WHEN SAID VENTING MEANS IS OPENED.